1. Field of the Invention
The invention relates to a video recorder comprising a control device by means of which the video recorder can be set to the "recording" mode, in which programs transmitted by at least one transmitter and received by the video recorder can be recorded on a record carrier, the transmitted programs each including an identification signal transmitted to identify a program, and comprising an index-signal generator for generating an index signal which can be recorded on the record carrier, the control device having a control connection with the index-signal generator, in such a manner that upon activation of the "recording" mode by the control device, this control device controls the index-signal generator in order to generate an index signal which is recorded on the record carrier so as to correspond to the beginning of the recording, and comprising a detection device provided to detect identification signals in the transmitted programs and to detect any identification signal change indicating a transition from one program to a subsequent program.
2. Description of the Related Art
Such a video recorder of the type defined in the opening paragraph is known in different versions. For example, a video recorder manufactured by the Applicant has been marketed under the type designation VR 333.
In the known video recorder, the control device for activating the "recording" mode is implemented by means of two microcomputers which communicate with one another. One of the microcomputers is also used for realizing the index-signal generator, which is adapted to generate an index signal which is also referred to as a VISS signal among experts, the acronym VISS standing for "Video Index Search System". In the known video recorder, such an index signal is recorded on the magnetic tape by starting the "recording" mode by the actuation of a key provided for this purpose on the video recorder or on a remote control device for the video recorder, so that such an index signal always marks the beginning of a recording. By means of the recorded index signal, this recorded index signal, and hence the beginning of a recording can be located very rapidly in a search mode.
The known video recorder further comprises a detection device for detecting identification signals contained in the transmitted program and to detect each identification signal change which indicates a change from one program to a subsequent program, the identification signals being the VPS signals known to those skilled in the art. The detection device in the known video recorder serves inter alia for automatically starting the "recording" mode in the video recorder when an identification signal to which the video recorder has been preprogrammed is detected, by the detection device, in the program received by the video recorder. As long as this identification signal to which the video recorder has been programmed is present in the received broadcast and is consequently detected by the detection device, the video recorder remains in the "recording" mode. In the known video recorder, the detection device also serves to cause the "recording" mode of the video recorder to be stopped when the identification signal to which the video recorder has been preprogrammed is no longer received, i.e., when an identification signal change occurs, which is detected by the detection device, after which the "recording" mode of the video recorder is stopped.
However, in the known video recorder, only the beginning of a recording can be located simply in an automatic search mode by searching for the index signal recorded at the beginning of a program.